The general way to solve these interesting questions is to state the conditions that a searched object must meet in the questions raised at the end of each interesting question.
Interesting questions are arranged according to the principle of easy before difficult, so if a reader starts with the first interesting question and works step by step, you will find that you have the ability to solve those interesting questions that are difficult for him. In order to help readers who walk into a dead end, every interesting question is accompanied by a "hint"-arranged at the bottom of the page-intended to guide readers' thinking in the right direction.
It also made me understand the meaning, function and story of percentage, such as the relationship between percentage and division, the relationship between decimal and fraction, the practical application and situation of percentage in life.
This book brought me into the wonderful world of mathematics and made me like interesting mathematics more.